1. The Field of the Invention
The present invention relates to a method and apparatus for selectively isolating portions of a well bore by use of a device known as a packer, and in particular, to a method and apparatus for expanding the packer in place.
2. The Prior Art
Many times, when completing wells, it is desirable to isolate specific zones which may be producing either gas or water, or some combination thereof, from a producing interval. One of the most commonly used methods for creating this isolation is by the use of external casing packers. These are assemblies which are inserted downhole and include an inflatable annular packing member. After the packer is properly positioned, the packing member is inflated outwardly to tightly engage the walls of the well bore thereby forming a seal. The known packers generally activated by injecting drilling fluid or cement into the inflatable packing member. The former system has the obvious drawback of requiring a constant pressure of drilling fluid to maintain the packing member inflated to the sealing condition. The latter system has the disadvantage that the cement may tend to shrink as it sets, and with age, resulting in at least partial deflation of the packing member and less than perfect seal.
The present invention intends to overcome the defects of the prior art by providing an improved external packer which is activated by a catalyst or activator solution and is inflated with a resin system that will consolidate when exposed to the catalyst.